


Boyish Envy

by ForbiddenArchive



Category: Fate/Grand Order
Genre: Genderswap, M/M, female to male
Language: English
Status: Completed
Published: 2020-12-16
Updated: 2020-12-16
Packaged: 2021-03-11 00:47:56
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,262
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28116423
Author URL: https://archiveofourown.org/users/ForbiddenArchive/pseuds/ForbiddenArchive
Summary: Mash, jealous of how lovable Astolfo appears, tries to wish for his appeal. She gets it all, literally.
Kudos: 6





	Boyish Envy

Chaldea. The last bastion standing against the incineration of Human History. A place where figures from the past and from fantasy stand together under the banner of humanity to try and save it from those that would try to harm it.

And a place where petty feelings ruled above all. Case in point, the young Mash Kyrielight, alias the Demi-Servant Shielder. She did her best to work together with her Master through thick and thin, to try and defend him to pay him back for what he had done for her. Yet here she was, in the storage closet, digging through trash to try and find something valuable.

It hadn’t been long ago since the young man that served as her Master had summoned that pink-haired Rider, and ever since then, he had just been unreachable. No matter how much she tried to get ahold of him, he always seemed to be occupied with something. Whether it was the boy or somebody else, it was like she was a ghost to him. It frustrated her to no end, and that’s why she was stooping so such desperate methods like the one she was about to attempt.

“They’ve got to be in here somewhere, I know Da Vinci told me that Master didn’t think for a second about using these things… He hasn’t even tried using them on Astolfo, why’s he saving them so much?” The eggplant-haired girl muttered to herself as she pulled herself out of another box, sighing in the process.

She just wanted to see him smile at her again. See him praise her for what a good girl she had been, for such a good job she had done, anything of that sort. She didn’t want him to remain so distant when their bond had been so tight. That’s why she needed the Holy Grails that they had gathered, the ones that were kept around for special occasions… The ones that had wish-granting abilities.

If Mash could just get her hands on one of them, all of her problems would be solved! She could wish for something pleasant like getting everything Astolfo ever cared about, and then she’d never have to be worried again! Worst case scenario, she’d have to wish for a new Master and hope that he couldn’t be seduced by pink-haired boys.

As she backed away to try and gather her bearings, she suddenly bumped into the wall and caused something to fall from the shelf above her. She rubbed the spot on her head where it had impacted, looking at the object on the ground… before her eyes widened in relief and surprise.

She had found a grail! She took a moment to look up, just to ensure that it wasn’t the only one which would make it a trap, but no, it was one of many grails that had been sitting on a shelf just barely out of human reach. It seemed like hiding the things like this was much more effective than one would assume, since nobody dared to actually look upward…

Well, this wasn’t the time to worry about security issues like that. it was time to focus on what was important. Namely, getting her wish! Oh, she couldn’t wait, she couldn’t wait at all. She gleefully got down on her knees and peered at the grail, thinking to herself about how to potentially turn it on…

“Hmmm… Miss Drake had one, and she just kinda wished on it, didn’t she?” Mash muttered to herself as she lightly picked up the golden grail, wondering if that might the only thing she had to do. She knew that the things could work for multiple wishes, so maybe she should start small…

She took a deep breath… “I wish to be naked.” She spoke and closed her eyes as she felt a tingling sensation on her body, making her imagine that she really did lose all her clothes. She opened her eyes moments later and was pleased to discover not a speck of fabric on her body, her nipples proudly standing erect due to the dull yet cold air in the storage closet…

It had worked, and the grail was still there. This was perfect! She’d just need to wish on it once more time, and then she could have Master all to herself! It was bulletproof, she couldn’t think of a better plan…

“I wish… I wish to have everything that makes Astolfo unique and special in my Master’s eyes so that I can be just as appealing to him!” She tried to word in such a way that the divine relic could properly comprehend her words, just so that it wouldn’t accidentally transform into a freak or something. She wasn’t a stranger to cursed wishes, but she didn’t know the actual specifics of what she was wishing for, so she could still get screwed over.

As the tingling started back up, she could feel the slim hairs on her body standing straight, almost as if she had been hit by a chill. But at the same time, she could definitely feel some changes, most importantly down below as she felt her hips widen almost inhumanly so. She couldn’t fit on a single chair by the time her hips had finished widening, and she’d have trouble fitting in any of her outfits just the same. But why would she need hips that big?

Mash let out a quick squeal as she felt a pressure building on her chest, slowly but surely flattening out her breasts until there was nothing left but a delicious flat torso with just the right amount of tone around the belly. She had unknowingly gotten stronger when she wasn’t looking, but in exchange, she had lost a bit of her feminine charm. Still, considering the overall curvature of her body combined with those fat hips of hers, it wasn’t going to be a problem, right?

The grail didn’t think so, as she felt another sensation growing between her thighs. Instead of a pushing sensation, this was a pulling and tugging sensation, as if it was trying to grab something inside of her and yank it out. It made her moan and cry out in pure pleasure, making it harder and harder for her to see or think straight. Not that it was easy to do so already, considering the wish was making her head foggier and foggier by the passing moments…

“It feels so good…” She muttered as she reached down, clenching her fist around the same area where the invisible force was tugging on her nethers, and slowly following its moves by stroking her hand back and forth, gasping and panting as the seconds ticked by. She could feel her body growing warmer and warmer, right up until her breaking point. A point that was punctuated by the sensation fading and something long and hard slipping into her hand…

Only after she felt the shaft slipping into her hand did her mind break free from its haze and realize something had gone horribly wrong. She wasn’t supposed to have a cock the size of her thigh, much less one at all! Why was there suddenly a huge penis hanging from her crotch? Where had her pussy gone? Why was she feeling so hot all of a sudden, and most importantly of all, why did she look like a genuine boy instead of a girl like she truly was?

Then the next part of the wish started washing over her. Or rather, Him. He wasn’t a girl at all, and he hadn’t ever been. The grail was rewriting his history from the ground up, erasing the parts that didn’t matter and replacing them with appropriate parts that had been blatantly stolen from the boy that he had envied. They now shared traits and histories, at least part of them.

He was still Mash Kyrielight, that much was still set in stone, and he was still a Demi-Servant, but instead of the horribly boring Galahad, he had become a host for Astolfo. Which came with its own perks and disadvantages. Firstly, he grew a cock that could break any woman that he’d ever try to fuck, and he was pretty certain it’d break certain men just the same. Secondly, his libido started skyrocketing due to the myth of Charlemagne and Astolfo going around and fucking so many unfaithful wives to prove a point. Thirdly, and most importantly, his morals completely vanished. All semblances of being careful and using restraint had completely been erased from his mind, leaving nothing more behind than a boy that had never ever been a girl before…

Mash licked his lips as his eyes snapped back to reality, now filled with a pink haze as he ran his hand along the length of his shaft. “Mmmm… I could really go for a good fuck right about now, but I have to calm this bad boy down first…” He mused to himself, giggling like a horny ditz as he furiously slammed his hand up and down, forcing his arousal higher and higher in turn. He wanted to cum, and when he wanted to cum, he didn’t hesitate!

Almost as if on cue, right as the boy was about to blow his load, he could hear the door to the closet open. “Mash? Are you in here? Da Vinci said that you looked really distraught, and… And I’m sorry I’ve been neglecting you lately, I want to make it up to you!” Gudao was at the door, finally showing up to support his Servant… shame that his Servant wasn’t exactly in the shape for support, much less caring about him like that anymore.

The black-haired boy flinched as he saw the huge-cocked Mash openly playing with himself right then and there, almost causing him to leave from the display. And yet, something was awfully alluring about it. “Y-You’re… A-Are you Mash..?” His words were wavering as he stumbled forward, slowly being pulled toward his Servant thanks to the smell wafting from his manhood.

“Ah! Master! You’re just in time! I’ve been wanting to blow my load, can’t you suck it all down?” Mash giggled as he grabbed ahold of his Master’s head, not at all caring that he was about to manhandle a young man that he once respected and adored, because those memories weren’t in his head any longer. All that remained was the sight of his fuckbuddy and Master, who always wore cute lingerie when they were working together, and they usually got up to some pretty freaky stuff whenever they saw a cute boy or girl. So, using him as a cock sleeve like this was perfectly normal in his mind!

Gudao gagged as he was forcibly shoved onto that cock, his throat bulging outward as the rod filled his body. At the same time, the musk and the feel of the manhood were changing him on a fundamental level, something that might’ve been caused by the lingering magic of the grail. Whatever was the case, his body soon mirrored that of the purple-haired boy’s, with the same excessive hips and cute enormous cock between his thighs. Even their current erect states mirrored, which made the way he was throbbing into the open air all the more adorable.

Both boys let out a simultaneous cry as they hit their peaks, causing plenty of cum to spew around. The black-haired master’s belly started filling up with liters of that sweet-scented salty seed, while his own cum was splattering across the floor in such a useless fashion. It wasn’t an uncommon sight, but it was still a wasteful thing to see. He could’ve blown his load inside a hot hole, instead, he was forced to submit to his lovely and horny Servant… Not that he minded that much, the two of them had grown tight ever since the Demi-Servant smashed his ass in and claimed him as a lover…

Once Mash was satisfied with his orgasm, he yanked the cock out of his Master’s mouth with a giggle. “Still as tight as ever, no matter how many times I’ve ruined your throat pussy! You’re the best, Master!” He chimed as he wrapped his cute arms around the boy’s bloated belly, squeezing a little bit of cum out in the process causing it to drool down his lips. “But I’m still so haaaard, can’t we go have a bit more fun?” The Demi-Servant pouted as he showed off his huge, rapidly throbbing cock, hoping that he could get permission…

Gudao licked the drooling cum from his lips as he giggled himself, getting onto his feet as he wrapped his arm around the back of his Servant. “Of course you can have some fun, I’ve been dying to have a good fuck too. Wanna try and see who can fuck the most before the sun goes down?” Since he embodied some of the aspects of Astolfo just as much as his Servant did, it was easy for him to get into a competitive mood…

“I’ll get the most, and you can just sit back and watch!” The Demi-Servant laughed, sprinting out of the closet with his Master right behind him, both leaving their former lives behind in the process. They didn’t care that they were likely about to turn the entire facility into horny boys like themselves, they were eager to fuck and that’s what mattered.

The cum-smothered Holy Grail laid silently within the abandoned Storage Closet, serving as the last remnant of the lives they had left behind.


End file.
